1. Field of the Invention
This invention relates to the field of solid propellant formulations and more specifically to energetic plasticizers for use in solid propellant compositions.
2. Description of the Prior Art
This invention generally relates to the preparation and use of 1,5-diazido-3-nitrazapentane. Solid propellants, gun propellants, and explosives are generally composed of oxidizers, binders, plasticizers, and sometimes a fuel. The oxidizers such as ammonium perchlorate and HMX are well known to the art. Hydrocarbon binders and inert plasticizers such as phthalates and triacetin are generally used. Finally, a fuel such as aluminum may be added. Recently, attempts have been made to replace the inert plasticizers with an energetic material so as to increase the specific impulse and burning rate of the propellant.
Recent work has indicated that azidomethyl nitramines ##STR1## constitute an attractive class of energetic plasticizers, U.S. Pat. Nos. 3,873,579 to Rosher and 4,085,123 to Flanagan et al. The process for preparing this class of compounds is based on first preparing a primary nitramine ##STR2## reacting it with formaldehyde and anhydrous HCl to form the chloromethylated product ##STR3## and finally treating this product with an ionic azide to form the azidomethyl nitramine ##STR4## The overall process is shown below: ##STR5## This process has two severe limitations. First, it requires a primary nitramine as the starting material. The synthesis of primary nitramines, themselves, requires a multi-step process. Furthermore, they are hazardous to handle because of the mobility of the acidic hydrogen atom. Secondly, this process is based on the preparation of a chloromethylated intermediate. Thus, it is only possible to produce an azidomethyl nitramine. Obviously, it would be of interest to have a method for preparing higher homologs such as azidoethyl nitramines, which would have improved physical properties, particularly sensitivity.